Manufacture of urea from ammonium carbamate



Patented Oct. 20, 1925.

UNITED STATES PATENT orrics.

NORMAN W. KRASE, OF CLARENDON, VIRGINIA, AND VERNIE LESESSNE GAIDDY,

DILLON, SOUTH CAROLINA, ASSIGNQ RS TO RICHARD C. TOLMAN, TRUSTEE:

MANUFACTURE OF UREA FROM AMMONIUM GARBAMATE.

No Drawing.

To all whom it may concern:

Be it known that we, NORMAN W. KRASE and VERNIE LEsnssNn GADDY, citizens of the United States, and residents, respective- 5 ly, of Clarendon, county of Arlington, and State of Virginia, and Dillon, county of Dillon, and State of South Carolina, have invented an Improvementin the Manufacture of Urea from Ammonium Carbamate, of which the following isa specification.

This invention relates to the manufacture of chemical compounds from solid condensates and has more especial reference to the manufacture of urea from ammonium carbamate.

The usual processes for producing urea from ammonium carbamate or for producing other compounds from solid condensates by heating the constitutents of such aration of ammonium carbamatc or other solid condensate directly in the autoclave in which the conversion by means of heating is subsequently carried out.

This method or procedure necessitates the alternate heating and cooling of the autoclave, since the condensate is prepared therein, and, the process, furthermore, is attended by various other difliculties. For example, in the case of the production of urea from ammonium carbamate, one process requires the use of liquid ammonia, another makes necessary the slow condensation of gaseous ammonium oarbamate in the autoclave.

This invention is an improvement in the method of preparing the charge of /ammonium carbamate or ammonium carbamate mixed with ammonium carbonate, or any other-solid condensate, such as, for instance, ammonium bicarbonate or ammonium carbonate, prepared from condensible gases or fluids for treatment in an autoclave and in the method of the introduction of this prepared charge into the autoclave.

The invention may be carried out substantially as follows, although the operacompounds in an autoclaveinvolvethe prep Application filed March 25, 1921. Serial No. 455,496.

tion may be varied in detail without departing from the spirit of. the invention or the scope of the claims.

The charge prepared in any suitable con briquettes, in the case of the charge for urea manufacture, approximately 1.1" meter; however, any other suitablepressure may be used.

The briquett-ing or forming apparatus will have a density of may conveniently be of such dimensions briquette, when placedthatthe resulting in the autoclave for conversion into urea, exactly fills the autoclave. If the autoclave is of such alength that the briquette can not be handled, the autoclave charge may be' made 'up of several shorter briquettes which may be loaded successively into the autoclave.

It should 'beespecially noted, as one of the novel features of this method of manu- "facture, that there is no necessity for alternate heating and cooling of the autoclave as is necessary when the charge is formed directly therein, since the-briquettes can be quickly droppedinto the autoclave.

Having thus described our invention, what We claim asfnew and desire to pro cure by Letters Patent, is p v 1. T e process of .making'urea' from-amixture of"a1nmonium carbamate'g-and iammonium carbonate, comprising compressing the mixturajoharging the compressed mix grams per cubic centi-- conveniently. produced or,

'ture into a-heatedautoclave and maintaining the heat of the autoclave.

2. The Process of making urea from ar'n VERN IE LESESSNE GADDY. 

